It seems there could be a scientific reason why a sneaky treat always tastes just that little bit better.

Researchers from Northwestern University, in Illinois, have found that people who are “primed with guilt” enjoy things more.

The research was led by Kelly Goldsmith, who said she first came up with the idea when a co-worker mentioned that she had just joined Weight Watchers.

Kelly Goldsmith recalls: “She said, <<Gosh, why does everything just taste better when you’re on a diet?>>.

“That got me and my advisor talking. Does stuff actually taste better when you’re on a diet? Does stuff taste better when you feel guilty eating it?”

The resulting study, published in The Journal of Marketing Research, was made up of six different experiments.

In the first researchers split participants into two groups and asked them to view six magazine covers.

Half looked at health related magazine covers and half looked at covers which were completely unrelated.

They were all then given chocolate bars for what they were told was a “taste study”.

All of those who had been reading about healthy eating reported that the chocolate tasted better than those who had not.

A second experiment split around 100 undergraduate students into three groups and asked them to describe three experiences in a few sentences.

It included times that they felt guilty, times that they felt disgusted, and the final third were asked to describe three random times.

Then all the students were given a chocolate truffle to eat.

Chocolate and other sneaky treats taste better when you are on a diet

All of the students who relived their guiltiest moments reported that the chocolate truffle tasted better than the other groups.

But the link between guilt and pleasure does not stop at food.

In another experiment, women were made to feel guilty and then shown online profiles of attractive men on a dating website.

The study found the women who had felt guilty prior to looking at men derived much more pleasure from the experience.

“Guilt is linked with pleasure because often times when we experience guilt, we experience pleasure,” Kelley Goldsmith says.

“I think for a lot of people these cognitive associations can form just based on what we called repeated co activation.

“When pleasure’s activated, guilt is activated, and so in our brains, over time, those two become connected.”